Currently, joints used for the pivotal connection of buckets and other work tools to lift arms and other linkages of work machines commonly include collet type joints and flag type joints. Both types of pin joints utilize a sleeve type bearing mounted in a first member, usually the lift arm or other link, and a pin or pin assembly attached to a second member, which is typically the bucket or other work tool. Collet pin joints include tapered collets which are pressed in or frictionally engaged with the second member for securing the pin or pin assembly in position. This makes the collet pin joints the stronger and stiffer of the two types of joints. However, because of the press or frictional fit, it is difficult to control the axial relationship between the collets and the bearing, necessitating the use of seals therebetween which are not sensitive to axial loading. To meet this need, the known collet pin joints are grease lubricated to allow grease seals to be used. But, this requires frequent greasing to avoid seizing, galling and/or breakage. As another limitation, the known collet pin joints use a pin assembly typically provided as a weldment or cartridge, which is not intended for replacement in the field. Flag type pin joints differ from collet pin joints in the use of one or more external members known as flags for retaining the pin or pin assembly within the bearing. This provides consistent axial length control such that oil seals can be used and oil as the lubricant, thus providing the advantage of requiring less frequent lubrication. The pins or pin assemblies of the flag type joints are also easy to remove and replace in the field. However, the flags have been found to be more prone to wear and breakage, resulting in higher than desired incidence of repair.
Thus, what is required is a pin joint that provides the strength and stiffness of a collet pin joint, but the axial length control and long intervals between lubrication and ease of serviceability of the flag type joints.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.